Many forms of devices are known for delivering particles of an abrasive material to a surface to be cleaned or otherwise abraded. Commonly, such devices have a nozzle through which an air or gas stream is delivered carrying particles of the abrasive in suspension, and in general, such nozzles are employed by directing the delivered stream against the surface to be cleaned or abraded. In my prior U.S. Pat. No. 4,174,571 above identified and also in prior U.S. Pat. Nos. 3,882,638 and 3,972,123, water is also delivered from the nozzle, the water stream being in the form of one or more jets arranged so that the water will impinge upon the surface being treated very close to or overlapping with the target area for the abrasive/air stream.
My prior patent identified above discloses the use of a water-soluble abrasive in a system of the kind just referred to, so that when the water stream joins the air/abrasive stream, a slurry is formed and the cleaning or abrasion is effected, at least in part, by means of such slurry.